Colossal negative magnetoresistance in the complex charge density wave regime of an antiferromagnetic Dirac semimetal

TL;DR

This study reveals that the antiferromagnetic Dirac semimetal CeSbTe exhibits colossal negative magnetoresistance due to charge density wave interactions and magnetic field effects, similar to phenomena observed in manganites.

Contribution

It demonstrates the occurrence of colossal negative MR in an antiferromagnetic Dirac semimetal with complex charge density wave behavior, expanding understanding of MR in topological materials.

Findings

CeSbTe exhibits colossal negative magnetoresistance.

Magnetic field induces semiconductor-metal transition.

Coupling between charge density wave and spin modulation observed.

Abstract

Colossal magnetoresistance (MR) is a well-known phenomenon, notably observed in hole-doped ferromagnetic manganites. It remains a major research topic due to its potential in technological applications. Though topological semimetals also show large MR, its origin and nature are completely different. Here, we show that in the highly electron doped region, the Dirac semimetal CeSbTe demonstrates similar properties as the manganites. CeSb$_{0.11}$Te$_{1.90}$ hosts multiple charge density wave (CDW) modulation-vectors and has a complex magnetic phase diagram. We confirm that this compound is an antiferromagnetic Dirac semimetal. Despite having a metallic Fermi surface, the electronic transport properties are semiconductor-like and deviate from known theoretical models. An external magnetic field induces a semiconductor-metal-like transition, which results in a colossal negative MR. Moreover, signatures of the coupling between the CDW and a spin modulation are observed in resistivity. This spin modulation also produces a giant anomalous Hall response.